1. Field
The present invention relates to a device and a method for oil pressure sensor fault sensing for a vehicle.
2. Description of Related Art
There is conventionally an electronic control unit (ECU) for engine control, which controls the operation of an internal combustion engine as a driving source of a vehicle. The electronic control unit includes a microcomputer (CPU) supplied with battery power according to an on/off operation of an ignition switch (main switch), and a time measuring section for measuring time. The time measuring section has an auxiliary power supply not involved in the turning on/off of the ignition switch. The elapsed time of an engine stop duration is measured, the time of the engine stop duration is read from the time measuring section after the microcomputer is started, and the time is used to determine whether a water temperature sensor is faulty see, for example, Japanese Patent Number 3489548 (Patent Document 1).
A constitution similar to the above constitution is considered for fault sensing for an oil pressure sensor system essential to an ordinary internal combustion engine. Break or failure detection for an oil pressure sensor system in such an oil warning system is made possible by monitoring a normally closed oil pressure sensor during an engine stop (oil pressure absence state).
However, the above constitution has the time measuring section within the ECU, and has the auxiliary power supply as a continuous power supply to measure the time of an engine stop duration. Thus, the number of parts within the ECU is increased, which leads to an increase in cost.